It would cost them more, and you can also improve your noise techniques using an adversarial AI. Techniques that are used to trick AI with image detection should also apply generally in finding patterns in signal noise. People say obfuscation isn’t true security, and they’re right but if you do it very well it can still be valuable in situations where real security is infeasible. I wouldn’t treat this as perfect protection, but just adding noise might make it hard to find relationships in the data.

See also: TrackMeNot, which does fake searches. I’ll be honest, I was hoping to play around with using the techniques of TrackMeNot for noise, too, but I’m not, at all sure, how to measure it’s effectiveness, unfortunately.